1. The Field of the Invention
This invention relates to cutting and piercing tools and more particularly to that class utilized in cutting and piercing cylindrical plastic protrusions associated with caulking gun cartridges.
2. Description of the Prior Art
The prior art abounds with cartridge tip cutting devices. U.S. Pat. No. 3,105,614 issued on Oct. 1, 1963 to W. A. Sherbondy and U.S. Pat. No. 3,189,226 issued on June 15, 1965 to W. A. Sherbondy disclose caulking gun apparatus each having a shearing knife operated by the trigger of the dispensing gun parallel to a portion of the handle of the apparatus containing an opening. In use, the tip of the cartridge is first inserted in the hole or opening and as the trigger apparatus is manually operated, the tip is sheared away.
The 1965 patent further teaches a spring member having a free pointed end used to bias the trigger apparatus arcuately outwardly from the handle and serving as a piercing tool to either puncture the plastic cylinder at the dispensing end of the cartridge or to break into a crusted layer of caulking material thereat.
Both of the aforementioned patents suffer the common deficiency of situating the opened portion of the dispensing end of the cartridge in contact with the caulking gun apparatus, thereby causing portions of the gun to become soiled with the caulking material extruding outwardly from the cartridge.